The present invention relates generally to the field of computer resource management, and more particularly to management of memory pages in a computing environment.
Live Partition Mobility (LPM) is a feature utilized in computer servers and virtual machine environments that allows a running logical partition (LPAR) to be relocated from one computer system to another computer system. In LPM, memory is copied asynchronously from one system to another to create a clone of a running partition with “dirty” pages being re-copied as necessary. LPM can be utilized to transmit data stored on memory pages from one system to another. A memory page is a fixed-length contiguous block of virtual memory. For example, a server computer includes dynamic random-access memory (DRAM), which is allocated to one or more LPARs of the server computer. The DRAM is divided into a pool of “chunks” of memory, and each chunk is referred to as a memory page.
A hypervisor or virtual machine monitor (VMM) is a piece of computer software, firmware, or hardware that creates and runs virtual machines. In an Active Memory Sharing (AMS) environment, a hypervisor can provide a loan of memory pages from LPARs that are not using the memory pages to LPARs that are experiencing increased memory pressure. AMS provides system memory virtualization capabilities, allowing multiple LPARs to share a common pool of virtual memory.